What shouldn’t I say when to a friend/acquaintance when their child dies?

Most people really don't know what to say to a family who has lost a child. It doesn't matter if the child was stillborn, one month old or 30 years old -- he or she was still someone's baby, and should be treated as such. Try to be understanding without saying you understand, because unless you have walked in their shoes, you don't know the grief and loss they are feeling. But if you are still looking for the right words, here are some topics to avoid:
"It's better now than when (the child) is older."
"Now you have an angel in Heaven."
"At least you didn't get too attached to him or her."
"I understand."
"I know what you are feeling, because I've lost (fill in the blank)."
"You're young, you can have more children."
"Everything happens for a reason."
"God doesn't give more than you can handle."
"Are you feeling better yet?"